There are a variety of substrate processing apparatuses which process substrates. For example, a substrate processing apparatus in Patent Literature 1 is configured such that an indexer block in which unprocessed substrates and processed substrates are stacked and a processing block in which a process such as cleaning is performed on substrates are connected via substrate inverting units and substrate rest parts. A transport robot specific to each block is disposed in each of the indexer block and the processing block.
A transport robot specific for the indexer block (main robot) which includes two arms independently driven back and forth is disclosed in Patent Literature 1. A substrate holding hand is provided at the distal end of each of the two arms, and is configured to be able to hold two substrates. Thus, a total of four substrates can be transported.